title: Sub-3-cycle vortex pulses of tunable topological charge.
abstract: Novel types of reflective spiral micro-electro-mechanical systems were used to generate few-cycle vortex pulses of variable topological charge from a Ti:sapphire laser oscillator. The phase profile of these components was controlled by varying the temperature. The temporal properties of the pulses were characterized with spatially resolved nonlinear autocorrelation. The beam structure resembles a slightly distorted Laguerre-Gaussian distribution. The different topological charges were indicated by detecting Poynting-vector maps with a programmable Shack-Hartmann sensor of enhanced angular sensitivity.
authors.forename: Martin
authors.initials: M
authors.lastname: Bock
authors.forename: Jens
authors.initials: J
authors.lastname: Brunne
authors.forename: Alexander
authors.initials: A
authors.lastname: Treffer
authors.forename: Stefan
authors.initials: S
authors.lastname: König
authors.forename: Ulrike
authors.initials: U
authors.lastname: Wallrabe
authors.forename: Ruediger
authors.initials: R
authors.lastname: Grunwald